Application of a micromembrane chromatography module to the examination of protein adsorption equilibrium

A micromembrane chromatography module based on a 96‐well plate design and enabling fast and simple separation of small amounts of proteins was used for the determination of binding capacities of lysozyme, bovine serum albumin, ovalbumin, bovine γ‐globulin, and human immunoglobulin G on a hydrophobic membrane Sartobind® Phenyl. Dependence of the binding capacity of the proteins on the ammonium sulfate concentration was examined in the salt concentration range of 0.5–2.0 mol L−1. An exponential increase of the binding capacity was observed for all proteins. Simple Langmuir one‐component isotherm was found suitable for the characterization of the effect of protein concentration in all cases. A combined effect of protein and salt concentrations was expressed via the Langmuir exponential isotherm and fitted the adsorption data for three of the investigated proteins well.